Spark plug



p 1940- c. E. GOTTERBA ET AL, 2,214,958

SPARK PLUG Filed April 24, 1939 TIA CLARENCE GOTTEEEA' Auausr R. LAYERPatented Sept. 17, 1940 PATENT orrlca SPARK PLUG Clarence E. Gotten-ha,Long Beach, and August R.

Layer, Walnut Park, Calif., assignors, by mesne assignments, to saidAugust B. Layer Application April 24, 1939, Serial No. 269,682

Claims.

This invention relates generally to spark plugs for use in internalcombustion engines.

It is a primary object of this invention to provide a spark plug for usein various types of internal combustion engines which will operateefficiently over long periods of use and under various types ofoperating conditions.

It is a particular object of this invention to provide a spark plughaving an annular spark I gap 'and embodying a disc or button below theshell of the plug as the electrode portion of the plug. It is a furtherobject of this invention in this connection to provide a plug whichtends to be self-cleaning.

II It is also an object of this invention to provide a spark plug whichmay be easily assembled, which cannot leak and which may be adjusted bya novel method. In this connection it is a particular object to providean electrode which is mounted in a shell having a tapered opening and toprovide means associated with the electrode and its insulation jacketfor mounting the electrode in the tapered opening in the shell. Moreparticularly, it is an object of this invention to provide an electrodewith a tapered member thereon adapted to be mounted in a.correspondingly tapered bore in the shell of the plug so that the plugmay be adjusted by grinding the surface of the tapered member.

These and other objects will be apparent from the drawing and thefollowing description thereof. Referring to the drawing which isfor-illustrative purposes only;

Fig. 1 is a sectional elevation of the plug of this invention; and

Fig. 2 is an elevation, partly in section of a modified form of theinvention.

More particularly describing the invention, reference numeral llindicates a shell of metal or other suitable material which is adaptedto be mounted in the threaded opening of the cylinder block of aninternal combustion engine by means of the lower threaded portion l2.This shell is provided with an internal tapered bore I3 which may bedescribed as frustro conical in shape.

Adapted to be mounted in the shell is an electrode assembly generallyindicated by reference 50 numeral H which comprises the electrode IS,

a jacket l6 of insulation material, such as mica or other suitablematerial, a retaining nut l1 and a terminal nut IS. The upper end of theelectrode i5 is provided with screw threads I9 55 to accommodate theaforementioned nut I1 and terminal nut It. At its lower end theelectrode I5 terminates in a disc portion or button 20.

The electrode assembly further includes a sleeve 22 which is preferablyshrunk on to the jacket l6 and may be formed of steel or other suitablematerial. The upper end of this sleeve is provided with screw threads 23to accommodate a retaining nut 24 which serves to removably secure theelectrode assembly in the shell I I. The outer surface of the sleeve 22is tapered 10 to correspond to the taper of the bore l3 of the shell i Iso that when the nut 24 is tightened the sleeve 22 will co-fit with thesurface of the bore [3 in the shell. Preferably the dimensions of thesleeve 22 are so proportioned to the dimenl5 sions of the bore l3 thatthe electrode button 20 will be spaced below the lower end of thethreaded portion of the shell ll a desired distance, thereby leaving aspark gap between the button and the shell as indicated generally byreference numeral 25.

With the construction outlined above there is provided a spark plughaving an annular spark gap 25 which tends to be self-cleaning and whichhas been found to resist corrosion g5 and fouling. In this connectionthe location of the button 20 below the lowermost end of the shell llfacilitates the self-cleaning action of the electrode since it providesfree access of the circulating gases within the cylinder to the spark 3ogap region.

The above construction also provides a means for positively seating theelectrode assembly within the shell and thus serves to prevent anypossibility of gases escaping through the spark 5 plug under the highcompressions used in present day internal combustion engines. In orderto adjust the spacing of the button of the electrode with relation tothe lower end of the shell it is possible to decrease this distance bymerely a grinding the surface of the steel shell 22. To increase thegap, the lower end of the shell may be filed or ground.

In Fig. 2 there is shown a modified form of the plug which is designedto have a greater 5 self-cleaning action and which differs from the plugof Fig. 1 only in that the electrode button or disc indicated in Fig. 2by reference numeral 20a is provided with a tapered or bevelled uppersurface 21 and the lower end of the shell Ila 5 is provided with acorrespondingly bevelled or tapered portion 28. With this constructionthere is somewhat less tendency for carbon or other particles to remainin the region of the spark plug and the plug therefore has a somewhatmore pronounced self-cleaning action than the plug of Fig. 1.

Although the invention has been particularly shown and described, it iscontemplated that various changes might be made without departing fromthe scope of the invention and it is intended to cover such changes ascome within the scope of the claims.

We claim as our invention:

1. A spark plug comprising: a shell having a tapered bore therethrough;an electrode; an insulating jacket mounted on said electrode; a sleevemounted on said jacket, said sleeve having a tapered surfacecorresponding in taper to the bore of said shell and having screwthreads at its upper end; and a retaining nut threadably mounted on saidsleeve for removably securing said sleeve and its associated parts insaid shell.

2. A spark plug as defined in claim 1 in which the jacket is formed ofmica and the sleeve is formed of steel.

3. A spark plug comprising: a shell having a tapered bore therethrough;an electrode terminating at its upper end in a screw threaded portionand at its lower end in a button; an insulating jacket mounted on saidelectrode; a retaining nut threaded on said electrode in abuttingrelation to said jacket; a terminal nut threaded on said electrode andabutting against said retaining nut; a metal sleeve mounted on saidjacket, said sleeve having a tapered surface corresponding in taper tothe bore of said shell and having screw threads at its upper end; and aretaining nut threadably mounted on said sleeve for removably securingsaid sleeve and its associated parts in said shell, said retaining nutbeing in abutting relation to the upper end of said shell.

4. A spark plug comprising: a shell having a tapered bore therethrough;an electrode having a disc at its lower end; an insulating jacketmounted on said electrode; a sleeve mounted on said jacket, said sleevehaving a tapered surface corresponding in taper to the bore of saidshell; and means cooperating with said sleeve for removably securingsaid sleeve and its associated parts in said shell so that the disc ofsaid electrode is spaced below the lower end of said shell.

5. A spark plug comprising: a shell having a tapered bore therethrough;an electrode terminating at one end in a sparking disk portion; aninsulation jacket on said electrode; and means for rcmovably securingsaid electrode and its associated jacket in said bore to position saidsparking disk portion in spaced relation with and beyond the end of theshell where the bore is of largest diameter.

CLARENCE E. GO'I'I'ERBA. AUGUST R. LAYER.

